Cloud Tryouts

Started by rcallicotte, July 21, 2008, 04:29:19 pm

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September 10, 2008, 03:15:36 pm #30 Last Edit: September 10, 2008, 03:17:17 pm by Xpleet
Believe it or not calico,

the reason those clouds look unrealistic is,

they are too detailed! Well not the mesh but the way the lighting strikes. You don't see so much bumpy details in real clouds, it might be there but you don't see it.

This pic is a good example: the lighting strikes more in wide locations and widely, rather than in small spots, the billowy details are simply overcast because the light penetrates the surface of the clouds. That is the problem why many peoples' clouds look so unrealistic.


Actually the next to the last image looks realistic.  I've seen clouds like that.  But, it isn't what I want.

I'm not going to continue to make clouds with such fervor in the future.  There are too many variables in TG2 clouds that do not mesh with what I understand.  It will take time for someone to hopefully document these things, when Planetside gets the necessary time.  Or not.  It might just be that making TG2 clouds entirely realistic has no particular future.
So this is Disney World.  Can we live here?


I understand your position Calico.

I'm very much getting to a 'fuck it' point with my deadlines.


While these certainly aren't your best clouds, the whole debate about 'realistic' or 'not realistic' looking clouds is flawed.  In terms of cloud shapes I think we can all agree that nature can come up with far stranger things than we can.  In the case of Calico's clouds the debate stems from the lighting and what you can or cannot see, but when you are comparing the render to reality, what sort of reality are you actually making the comparison to?  If you are comparing it to a photograph, is the photograph exposed for detail in the clouds or detail on the ground or is it an HDR photograph.  All three will give you vastly different lighting and detail representations.

If the argument is that you shouldn't be able to see the details in the clouds (even though they are there) and you want to simulate an overexposed photograph, then simply crank up the light exposure setting in the render camera node until you get to the point where you are getting blown out highlights to match whatever medium you are calling reality.

In regards to your latest clouds, perhaps the problems you are facing do not stem so much from the cloud settings, but from sun and atmosphere settings.  Perhaps if you were to closely study a picture of the clouds you are trying to duplicate and make careful note of where exactly the sun is located spatially you would be able to more accurately make the clouds that you are trying to.  At the very least it would take a couple more elements out of the equation. 


Quote from: RArcher on September 10, 2008, 05:21:21 pm

In regards to your latest clouds, perhaps the problems you are facing do not stem so much from the cloud settings, but from sun and atmosphere settings.

i agree totally... all the clouds (almost all) are rendered with a "basic" atmosphere (so it seems) maybe by tweaking these settings the result will be far better (i am pretty sure of it) ;)

- try at least a 4/2 'haze and bluesky)
- and raise the height to 4000 and 10000 (for atmo and bluesky too)
- what is your contrast setting ?
well... maybe i'm wrong but that's where i would begin  :D

tweaking the cloud is great but if the atmo doesn't fit your goal...


I also agree.  Most clouds look much better with at least tweaked lighting and also atmosphere.  I have basically given up at creating "realistic" clouds for the time being.  Right now I am working of figuring out good lighting and atmosphere combinations that will enhance the clouds and the ground of my scenes.


Calico, I actually think your first recent post (not the 2nd without distance shader) was quite nice. It was only the darkness and gray color of the clouds that looked unrealistic to me. If you brightened them up I think they'd be some of the better I've seen posted here.

As for the difficulty of creating truly realistic clouds, this is not just a TG2 issue. There isn't a single application I know of that has successfully solved this problem in an easy to control and consistently reproducible way. The most realistic clouds in Hollywood come from high-end dedicated tools and have taken weeks or even months of tweaking to get right (see Stealth for example of Digital Domain's "Storm" volumetrics renderer in action). So I don't think your efforts are wasted, nor do I think you would have much more success in any other application. In fact from what I have seen TG2 gives you the best starting point right now.

Cloud and atmosphere realism is also an area that I am particularly interested in, and I think Matt shares that interest. Once the foundational work on TG2 is mostly out of the way there will be more time for tweaking of the shaders and controls for maximum realism and ease of use.

Without a doubt we do want to make TG2 easier and more fun to work with, but it's also very challenging to take these systems which are extremely complex and lay on top of them a simple and functional interface. What we have right now is essentially a first pass. Hopefully in the future there will be time for improvements in these areas. In the meantime I encourage you to keep experimenting as time and enthusiasm for your projects allows.

- Oshyan


I think ultimately this would be a worthy goal for cloud realism. Maybe planetside should talk to these university guys?


Thanks everyone.  I worked on this project for about 2 months.  LOL  So I'm giddy crazy and burnt toasty a little on the edges.  I've watched storm clouds for weeks and blah, blah, blah.

To be clear, TG2 has the coolest clouds I've ever seen in any application ever.  It's just I couldn't exactly reproduce something I saw in nature that was so cool.  I came close, though.  It was from a real cloud that I studied and studied and studied...from my porch.  It was outside.

The next thing I plan to do with this is to get a decent render and then I might share the file, if there are interested experimenters.   ;D
So this is Disney World.  Can we live here?



I think its great that you've done all this research.  It only brings you closer to your goal.  And don't feel all alone.  My spare time is usually spent researching and testing concepts like clouds, surfaces, lighting, etc.  We wouldn't be where we are today without all that time spent.

It looks like you've made phenomenal progress with the cloud work you've been doing, and I'd love to see more.

mood-inspiring images and music


I have intentionally not done any postwork so I get the clearest criticisms.  This is after tuning the lighting.  I think something looks too unrealistic and the little blobs here and there look out of place.  Any ideas would be nice.
So this is Disney World.  Can we live here?


Wow this is getting there though!  Maybe increase cloud density just a bit more?
mood-inspiring images and music


The stills in that research paper look very impressive, though the videos a bit less so. We're always interested in ways to improve the shading systems in TG2 so it's something to look into.

Calico, your latest cloud looks quite nice. I agree with Moodflow that density or edge sharpness increase may help. The edges somehow seem just a little too transparent. Otherwise the shape and shading are very nice. I would brighten the clouds a bit, either through cloud colors, or increasing exposure, and then of course increase samples. You ought to have a very good result on your hands at that point.

- Oshyan


Yes, please let Matt know about the link i posted.   :)


You made massive changes in your cloud setup. It looks quite different now from what you originally posted way back in the past. And guess what? I DO use the first *.tgd you posted in the file sharing section in an image that is rendering right now as I write :P :P :P
As I am not that sophisticated with TG2 yet (I still didn't take the time to learn some basic stuff 8)) I just added some more nodes to yours et voilĂ , the clouds look considerably different now. What I don't know at the moment is if I just overwrote your clouds with another clip file that I used, I'm not quite sure how this node-thing works and how I have to attach them together.
But I wandered from the subject... coming back I have to say that I am very sympathetic towards your efforts! You still may be lacking the technical knowledge of every slider there is to fiddle with but don't underestimate your knowledge concerning this matter. I'll keep my fingers crossed for your work because it takes TG2 to a point where things are actually are beginning to look like they should ;D I'm just speaking of clouds here! Seems they're the most difficult thing to do, since most images are really brilliant but when it comes to clouds they often lack something... and so everybody that puts some heart in the developement of that area should be venerated :)
Where was I going with all this...? Umm, well, I hope you will continue your efforts and post them sometime in the future!!! :P
What you wish to kindle in others must burn within yourself. - Augustine